1. Field of the Invention
The present invention is broadly concerned with improved methods and products for the thermal degradation of unwanted substances involving contacting such substances with a particulate metal composition in the presence of water and an alkali metal salt. More particularly, the invention pertains to such methods and products wherein the metallic compositions include respective quantities of particulate iron and magnesium, and preferably lesser amounts of particulate aluminum and zinc; such metal compositions can be used to thermally degrade materials such as agricultural manures to a small volume without any adverse environmental impact.
2. Description of the Prior Art
Agricultural areas involved in large-scale swine production face an increasingly difficult problem in disposing of swine manure and wastes. Indeed, in certain locales, government regulations are in place which severely limit the right of swine producers to dispose of such wastes in conventional ways; in some instances, these restrictions threaten to put such producers out of business or impose such costs as to make further production impractical.
There are a number of other industries that give rise to significant waste problems. Among these are packing house operations, oil refineries and the electrical utility industry because of the prior use of polychlorinated biphenols. Here again, these industries face evermore stringent environmental regulations making disposal problems a significant business issue.
Powdered metal compositions have been provided in the past for production of heat and hydrogen gas. For example, U.S. Pat. Nos. 4,017,414 and 3,993,577 describe iron and magnesium-containing compositions designed to generate relatively low temperatures with the evolution of hydrogen gas. The particular utility described in these references is that of replacing lost body heat for undersea divers or combat troops, or for heating machinery or instruments in remote or cold areas.